ModelViewSet Django Rest Framework

Model viewset comes with default action create(), retrieve(), update(), partial_update(), destroy() and list(). All these action are the result of multiple inheritance of mixins. By the same, it supports DefaultRouter from rest framework routers providing a huge advantage as we no longer have to deal with writing URL configuration ourselves.

Now the real question is when does the model viewset becomes handy?🤔😕

📌Suppose that we need to build an API where we can create, read, update and delete student.

How would you make an API? By using a function based view? By using APIView of class based view? By Using generic view? or By using viewset?

Any of the view above can give us an API to create, read, update and delete the student. But the appropriate solution would be using a model viewset.✔️ Writing a code with a function based view apiview() and class based APIView in this case would result into long lines of codes. We have to write each line of codes and configure our URL for all the methods by ourselves. Similarly, generics is also not an appropriate solution as it requires two views ListCreateAPIView and RetrieveUpdateDestroyAPIView to handle all the CRUD operation. On top of that, it also requires URL configuration. So model viewset is a perfect fit to this case as it can handle all the url for each action by itself and does not require two or more views like generics.

Now let’s build and API with ModelViewSet

Model

from django.db import models


class Student(models.Model):
    first_name = models.CharField(max_length=10)
    last_name = models.CharField(max_length=10)
    email = models.EmailField()
    age = models.PositiveSmallIntegerField()
    number = models.CharField(max_length=15)

Views

from rest_framework import viewsets

from Common.serializers import StudentSerializer
from Common.models import Student


class StudentViewSet(viewsets.ModelViewSet):
    serializer_class = StudentSerializer
    queryset = Student.objects.all()

URL

from rest_framework.routers import DefaultRouter
from .views import StudentViewSet
r = DefaultRouter()
r.register('student', StudentViewSet, basename='student')

urlpatterns = [
] + r.urls

In views, just two lines of code serializer_class and queryset in model viewset build an entire API and fulfilled the requirement. Now it creates all the action by itself using provided queryset and serializer class. If we dig little deep, all those actions are from mixins.

class ModelViewSet(mixins.CreateModelMixin,
                   mixins.RetrieveModelMixin,
                   mixins.UpdateModelMixin,
                   mixins.DestroyModelMixin,
                   mixins.ListModelMixin,
                   GenericViewSet):
    """
    A viewset that provides default `create()`, `retrieve()`, `update()`,
    `partial_update()`, `destroy()` and `list()` actions.
    """
    pass

Conclusion: ModelViewset is a viewset for CRUD activities on data model that is relatively simple to configure. If we want to build a REST API for an object defined in our models, ModelViewSet is the quickest method to expose our API.